In general, the invention relates to the field of optical stimulation of nerve cells, i.e., of stimulation by light. The invention thus relates to the field of optogenetics. The development of optogenetics, of the sensitization of normal nerve cells to light by genetic techniques, nurtures the hope of being able to use light to treat a range of diseases by temporally and spatially selective activation or inhibition of neuronal structures. Current systems are based on the stereotactic placement of electrodes and light sources directly in brain tissue or on the surface of the brain. This is associated with complicated surgical procedures and corresponding risks. Furthermore, the necessary stereotactic planning complicates broad applicability.
Moreover, the implantation of the light-generating structures leads to a not negligible heat input in the brain. To avoid brain damage, the possible attainable output density of the light signals is greatly limited.